Dataset Information

TFF1 Induces Aggregation and Reduces Motility of Helicobacter pylori.

ABSTRACT: Gastric cancer is considered one of the most common malignancies in humans and Helicobacter pylori infection is the major environmental risk factor of gastric cancer development. Given the high spread of this bacterium whose infection is mostly asymptomatic, H. pylori colonization persists for a long time, becoming chronic and predisposing to malignant transformation. The first defensive barrier from bacterial infection is constituted by the gastric mucosa that secretes several protective factors, among which is the trefoil factor 1 (TFF1), that, as mucin 5AC, binds the bacterium. Even if the protective role of TFF1 is well-documented, the molecular mechanisms that confer a beneficial function to the interaction among TFF1 and H. pylori remain still unclear. Here we analyze the effects of this interaction on H. pylori at morphological and molecular levels by means of microscopic observation, chemiotaxis and motility assays and real-time PCR analysis. Our results show that TFF1 favors aggregation of H. pylori and significantly slows down the motility of the bacterium across the mucus. Such aggregates significantly reduce both flgE and flaB gene transcription compared with bacteria not incubated with TFF1. Finally, our results suggest that the interaction between TFF1 and the bacterium may explain the frequent persistence of H. pylori in the human host without inducing disease.

SUBMITTER: Eletto D

PROVIDER: S-EPMC7918695 | biostudies-literature | 2021 Feb

REPOSITORIES: biostudies-literature

ACCESS DATA

Publications

TFF1 Induces Aggregation and Reduces Motility of Helicobacter pylori.

Eletto Daniela D Vllahu Megi M Mentucci Fatima F Del Gaudio Pasquale P Petrella Antonello A Porta Amalia A Tosco Alessandra A

International journal of molecular sciences 20210212 4

Gastric cancer is considered one of the most common malignancies in humans and Helicobacter pylori infection is the major environmental risk factor of gastric cancer development. Given the high spread of this bacterium whose infection is mostly asymptomatic, H. pylori colonization persists for a long time, becoming chronic and predisposing to malignant transformation. The first defensive barrier from bacterial infection is constituted by the gastric mucosa that secretes several pro ...[more]

PMID: 33673347

Similar Datasets

Project description:BackgroundThe hepatocyte growth factor (HGF) receptor, c-Met, is strongly implicated in late-stage cancer progression and poor patient prognosis. The stomach pathogen, Helicobacter pylori ( H. pylori ), was recently proposed to stimulate c-Met phosphorylation dependent upon interaction of c-Met with the bacterial CagA protein required for H. pylori -induced cancer cell motility and invasion.Materials and methodsIn this report, we employed short hairpin RNA (shRNA), western blot analysis using antibodies recognizing phosphorylation at discrete c-Met residues, and immunofluorescence microscopy to investigate the CagA-c-Met interaction.ResultsThe data showed that shRNA-mediated c-Met knockdown did not reduce H. pylori -induced cell motility, suggesting that c-Met was not required for motility. Surprisingly, c-Met knockdown did not reduce the level of an H. pylori -induced protein recognized by a phospho-c-Met antibody. This 125 kD protein was 10 kD smaller than c-Met, suggesting that H. pylori did not phosphorylate c-Met but cross-reacted with another protein. This hypothesis was confirmed when c-Met phosphorylation inhibitors did not lower the levels of the bacteria-induced 125 kD protein, and c-Met immunoprecipitation (IP) did not detect this 125 kD protein from H. pylori -treated lysates. This protein was identified as a product of antibody cross reactivity with phosphorylated CagA. We also confirmed that CagA interacts with c-Met, but this interaction may have caused previous authors to misinterpret phosphorylated CagA as c-Met phosphorylation. Finally, pretreatment with the proteasomal inhibitor, lactacystin, caused prolonged HGF-induced c-Met phosphorylation and facilitated a CagA-negative H. pylori to stimulate AGS cell motility, suggesting that sustained c-Met phosphorylation compensates for the loss of CagA-dependent signaling.ConclusionsThese data demonstrate that H. pylori stimulates cancer cell motility independent of the c-Met receptor. We further hypothesize that although H. pylori does not target c-Met, the bacteria may still utilize c-Met effector signaling to stimulate CagA-independent cancer cell motility, which may provide a further mechanism of H. pylori -dependent gastric cancer progression.

Project description:Helicobacter pylori is a bacterial pathogen that can cause many gastrointestinal diseases including ulcers and gastric cancer. A unique chemotaxis-mediated motility is critical for H. pylori to colonize in the human stomach and to establish chronic infection, but the underlying molecular mechanisms are not well understood. Here we employ cryo-electron tomography to reveal detailed structures of the H. pylori cell envelope including the sheathed flagella and chemotaxis arrays. Notably, H. pylori possesses a distinctive periplasmic cage-like structure with 18-fold symmetry. We propose that this structure forms a robust platform for recruiting 18 torque generators, which likely provide the higher torque needed for swimming in high-viscosity environments. We also reveal a series of key flagellar assembly intermediates, providing structural evidence that flagellar assembly is tightly coupled with biogenesis of the membrane sheath. Finally, we determine the structure of putative chemotaxis arrays at the flagellar pole, which have implications for how direction of flagellar rotation is regulated. Together, our pilot cryo-ET studies provide novel structural insights into the unipolar flagella of H. pylori and lay a foundation for a better understanding of the unique motility of this organism.ImportanceHelicobacter pylori is a highly motile bacterial pathogen that colonizes approximately 50% of the world's population. H. pylori can move readily within the viscous mucosal layer of the stomach. It has become increasingly clear that its unique flagella-driven motility is essential for successful gastric colonization and pathogenesis. Here we use advanced imaging techniques to visualize novel in situ structures with unprecedented detail in intact H. pylori cells. Remarkably, H. pylori possesses multiple unipolar flagella, which are driven by one of the largest flagellar motors found in bacteria. These large motors presumably provide higher torque needed by the bacterial pathogens to navigate in viscous environment of the human stomach.

Project description:Helicobacter pylori (H. pylori) is a pathogen contributing to peptic inflammation, ulceration, and cancer. A crucial step in the pathogenic sequence is when the bacterium first interacts with gastric tissue, an event that is poorly understood in vivo. We have shown that the luminal space adjacent to gastric epithelial damage is a microenvironment, and we hypothesized that this microenvironment might enhance H. pylori colonization. Inoculation with 106 H. pylori (wild-type Sydney Strain 1, SS1) significantly delayed healing of acetic-acid induced ulcers at Day 1, 7 and 30 post-inoculation, and wild-type SS1 preferentially colonized the ulcerated area compared to uninjured gastric tissue in the same animal at all time points. Gastric resident Lactobacillus spp. did not preferentially colonize ulcerated tissue. To determine whether bacterial motility and chemotaxis are important to ulcer healing and colonization, we analyzed isogenic H. pylori mutants defective in motility (ΔmotB) or chemotaxis (ΔcheY). ΔmotB (10(6)) failed to colonize ulcerated or healthy stomach tissue. ΔcheY (10(6)) colonized both tissues, but without preferential colonization of ulcerated tissue. However, ΔcheY did modestly delay ulcer healing, suggesting that chemotaxis is not required for this process. We used two-photon microscopy to induce microscopic epithelial lesions in vivo, and evaluated accumulation of fluorescently labeled H. pylori at gastric damage sites in the time frame of minutes instead of days. By 5 min after inducing damage, H. pylori SS1 preferentially accumulated at the site of damage and inhibited gastric epithelial restitution. H. pylori ΔcheY modestly accumulated at the gastric surface and inhibited restitution, but did not preferentially accumulate at the injury site. H. pylori ΔmotB neither accumulated at the surface nor inhibited restitution. We conclude that bacterial chemosensing and motility rapidly promote H. pylori colonization of injury sites, and thereby biases the injured tissue towards sustained gastric damage.

Dataset Information

TFF1 Induces Aggregation and Reduces Motility of Helicobacter pylori.

Publications

TFF1 Induces Aggregation and Reduces Motility of <i>Helicobacter pylori</i>.

Similar Datasets

OmicsDI is part of the ELIXIR infrastructure

Tweets